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From: Frank.Neumann@arbi.informatik.uni-oldenburg.de (Frank Neumann)
Newsgroups: comp.sys.amiga.graphics
Subject: Re: IFF formats
Message-ID: <4353@uniol.UUCP>
Date: 24 Jan 91 18:44:11 GMT
References: <1991Jan23.221325.20449@cunixf.cc.columbia.edu> <1991Jan24.022455.6950@lavaca.uh.edu>
Organization: University of Oldenburg, Germany
Lines: 35

Hi,
jet@karazm.math.uh.edu ("J. Eric Townsend") writes:
>In article <1991Jan23.221325.20449@cunixf.cc.columbia.edu> yk4@cunixb.cc.columbia.edu (Yong Su Kim) writes:
>>Are there different standards for IFFs on the Amiga?
>>I have an IFF converter for the Apple IIGS which can recognise IFFs
>>taken directly from the Amiga including HAM IFFs, but it cannot view
>>IFFs which haven been converted using programs like PBMplus, FBM, and
>>Alchemy. 

>Sounds like sloppy programming.  I've never had IFF problems as long
>as I stick to Amiga programs, but pbmplus has thrown some curves in
>my direction.  Unfortunately I haven't the time to figure out exactly
>where it goes goofy.

>Anybody else have an idea?
Well - I _SUSPECT_ a reason might be that (for instance) ppmtoilbm creates
pictures WITHOUT compression, that is CompressionFlag in the BMHD(?)
chunk is zero. And in fact some programs think that anyway pictures are
ALWAYS compressed - (indeed, a self-written small utility does this,
too :-}) - so they run into some difficulties uncompressing this.
Another reason might be the CAMG chunk which is also not recognized
by all programs.
One solution to the problem is: Take something liek Butcher or Pixmate,
load the picture and re-save it. Afterwards it will be (usually) in
compressed form.
Second/third solution: Re-write your Apple IFF viewer / ppmtoilbm.c :}

Hope this helps.
Frank
-- 
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